1. Field of the Invention
The invention relates to an error detection circuit interrupter device that includes a detection circuit for determining whether an error has occurred in an exterior circuit and includes an interrupter device for stopping current flow to the exterior circuit when an error has been detected. More particularly, the invention relates to a ground fault circuit interrupter device (GFCI) that includes a detection circuit for determining whether a ground fault has occurred in an exterior circuit and includes an interrupter device for stopping current flow to the exterior circuit when a ground fault has been detected.
2. Description of the Related Art
Fault or error detection devices are well known in the art to provide additional safety for electrical components. A specific type of fault or error detection device is know as a GFCI device. In operation, a GFCI type device supplies electricity to an exterior circuit and opens an outlet circuit when a ground fault occurs in the exterior circuit, i.e., when a portion of a circuit that is plugged into the outlet becomes grounded. For example, if a hair dryer is negligently dropped into a bathtub, electricity may flow from the hair dryer circuit to ground through the bathtub water. A person might be part of the current path to ground. An electrical outlet provided with a GFCI device will detect such a ground fault and, almost instantaneously, open the outlet circuit to prevent current from flowing from the hair dryer circuit to ground. Although the GFCI device is described above as being associated with an outlet, the typical GFCI device can be associated with other different types of electrical junctures.
Conventional GFCI devices include a detection circuit that compares the current leaving the outlet circuit to the current returning to the outlet circuit. When there is a pre-set differential between the leaving and returning outlet currents, the GFCI opens the outlet circuit and indicates that a ground fault has occurred. The detection circuit can be constructed in a number of different ways, including providing a differential transformer for sensing the imbalance in the current flow. In addition, there are many different structures that have conventionally been used to open the circuit once the ground fault has been detected. For example, some conventional GFCI devices use a trip coil to open the outlet circuit. A test and reset button are also typically provided on the GFCI device for testing whether the device is functioning properly and for resetting the device after testing or after the device has been tripped. Conventional GFCI devices are often complicated structures that require sophisticated manufacturing processes to ensure that they work properly and safely. Several other drawbacks exist in the conventional GFCI devices, including high manufacturing cost, poor reliability, poor endurance, potential safety concerns due to excessive heat generation and/or poor reliability, and general aesthetic and ergonomic drawbacks.
An object of the invention is to provide an fault/error detection device that is economic to manufacture, requires as few parts as possible and operates at a high level of reliability. Another object of the present invention is to provide a GFCI device that requires no more than one splice and no more than one pair of contacts along each current path located in the GFCI device. Yet another object of the invention is to provide a GFCI device that includes a cantilevered contact which can be opened to prevent current flow there through by an activation device that moves in a linear motion. Another object of the invention is to provide a GFCI device that includes a transformer boat and a solenoid bobbin that snap onto the circuit board and are located adjacent each other to provide added rigidity to the circuit board structure. A further object of the invention is to provide a GFCI device that has a linearly actuatable test switch that is simple to manufacture and operates reliably. Specifically, it is an object of the invention to provide a GFCI device in which the test switch includes a cantilevered integral extension from the output contact bar such that it can be bent by a one piece linearly actuated test switch to make contact with a test circuit and cause the GFCI device to trip. Yet another object of the invention is to provide a GFCI device with a housing that is easy to install and includes improved ergonomic features. Another object of the invention is to provide a GFCI device that is simple to manufacture and includes as few parts as possible while also providing the structural stability necessary for the device to be tested on a regular basis. A further object of the invention is to reduce the heat that occurs along the current path by minimizing the number of electrical splices (e.g., solders and welds) along the current path. Another object of the invention is to eliminate the use of separate bus bars or wires attached between the input line and a conductor that runs through the transformer. A still further object of the invention is to provide a separator that is integral with the middle housing to separate the conductors running through the transformer, thereby eliminating the need for a cover over the transformer. Another object of the invention is to provide a GFCI device that will not burn out after it is tripped by including a xe2x80x9cdeadxe2x80x9d mode or xe2x80x9cdesensitizedxe2x80x9d mode that turns off the ground fault detection device once it is tripped until it is reset. Yet another object of the invention is to provide a GFCI device that includes a test light indicator that will indicate when the GFCI device has been tripped and whether the GFCI device is wired correctly.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described, the invention provides a GFCI device for stopping current flow through a first circuit when a ground fault has been detected in the first circuit, the ground fault circuit interrupter device including a housing, a substructure located in the housing, a ground fault detector located on the substructure and capable of detecting whether a ground fault has occurred in the first circuit, a current path structure located on the substructure and having a first end terminating at an input connector and a second end terminating at an output connector, the current path structure including no more than one electrical splice, and a pair of contact points located in the current path structure and displaceable from each other to open the current path structure and cause current to stop flowing in the first circuit when the ground fault detector detects that a ground fault has occurred. Although only one current path is described above, the invention typically includes two current path structures including a hot current path and a neutral current path.
In another aspect of the invention, a ground fault circuit interrupter device for stopping current flow through a first circuit when a ground fault has been detected in the first circuit includes a housing, a substructure located in the housing, a ground fault detector located on the substructure and capable of detecting whether a ground fault has occurred in the first circuit, and a current path structure located on the substructure and having a first end terminating at an input connector and a second end terminating at an output connector, the current path structure including no more than three separate continuous structures and a pair of contact points, the contact points being displaceable from each other to open the current path structure and cause current to stop flowing in the first circuit when the ground fault detector detects that a ground fault has occurred.
In yet another aspect of the invention, a ground fault circuit interrupter device for stopping current flow through a first circuit when a ground fault has been detected in the first circuit includes a housing, a substructure located in the housing, a ground fault detector located on the substructure and capable of detecting whether a ground fault has occurred in the first circuit, and a current path structure located on the substructure and having a first end terminating at an input connector and a second end terminating at an output connector, the current path structure including, an input terminal that is a continuous structure having a first end and a second end, the first end of the input terminal integrally formed with the input connector, a first contact point and a second contact point, a first contact arm that is a continuous structure having a first end and a second end, the first end of the first contact arm connected to one of the first contact point and the second end to the input terminal, and an output terminal that is a continuous structure having a first end and a second end, the first end of the output terminal connected to one of the first contact point and the second end of the first contact arm, and the second end of the output terminal integrally formed with the output connector, wherein the second contact point is located adjacent the first contact point and on one of the second end of the input terminal and the second end of the first contact arm such that the first and second contact points are biased into contact with each other and are displaceable from each other to open the current path structure and cause current to stop flowing in the first circuit when the ground fault detector detects that a ground fault has occurred.
In another aspect of the invention, a method of making a ground fault circuit interrupter device includes providing a substructure having a ground fault detector and current path structure located thereon, the current path structure including a first one piece output terminal with integral outlet connector, a first one piece contact arm, a first pair of contact points, and a first one piece input terminal with integral inlet connector, connecting the first contact arm to one of the first output terminal and the first input terminal by a splice type connection, and connecting the first contact arm to the other of the first output terminal and the first input terminal via the first pair of contact points.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.